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You should also be able to email chrysler and request your build sheet that will have every option about your truck listed on it (including gear ratio).
 

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Discussion Starter · #5 ·
My build sheet says

DJMS 205MM HD Front Axle
DMDS 3.55 Rear Axle Ratio
DRBS Corporate 9.25 LD Rear Axle

Don't know why I didn't look there before. Now can someone decipher for me please?
 

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I can't comment on the front axle, but the rest means you have 3.55 gearing (pretty typical) and it is the 9.25" axle (standard on all ram 1500 models; this is just basically a name, you can just ignore the 9.25"....it is basically just an identifier). If you don't have anything (probably just under those items) that says "anti spin differential" or something similar to this then you have an "open" differential, which means both wheels won't provide torque to the ground, only one wheel will. Common "lay mans term" for when both wheels provide torque to the ground is posi traction...
 

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Yeah many 4.7L guys do that. I think 4.10's is tall enough, I'm afraid of losing hwy mpg though. Also, on the drag strip (depending on gear ratio and tire size) higher numerical gearing is not always better...
 

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Since the 4.7L is a smaller engine and has less torque than the hemi, higher numerical gearing is a way to compensate and make up for this. It's like riding a multi speed mountain bike, if you are in a low gear it is extremely easy to pedal at low speeds, but is very hard to go fast, but if you are in a high gear it is extremely difficult to pedal at low speeds but very easy to go fast. The 4.7L is more of a high revving engine, so it makes some sense to have higher numerical gearing vs the hemi, but IMO 4.56 is too much (depending on tire diameter). I would like to go to 4.56, but I think it'd kill my mpg.

Gearing is a way of torque multiplication. If you have 100 lb ft of torque at the rear of the transmission and have 3.55 gearing then you have 355 lb ft of torque at the wheels. By simply changing to 4.56 gears you now have 456 lb ft of torque at the wheels...
 

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I installed 4.56's (well a whole gm 14bolt and dana 44 to be honest) in my truck and it made a world of difference. I also installed the jeep 5-45rfe TCM (since my truck is an 02). That coupled with 305/70/16's made for a pretty nice overall set up with much more power and better fuel mileage than I was getting before
 

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what i found online

Chrysler 9.25
Application: 1500, 1500 4x4 All Engines

Capacity: 3,900 lbs
type semi-floating
Ratios 3.21, 3.55, 3.92
Ring gear diameter 9.25"
Ring gear face width 1.375"
pinion mounting overhung
pinion shaft diameter 1.88" inner
1.31" outer
Differential pinions two
axle shaft material Induction Hardened
diameter at bearing 1.62"
axle spline pitch 1.29"
Spring Centers 44.50"
Fluid capacity (2/4WD) 4.75/4.75 pints
wheel bearings Cylindrical Roller
 
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